Electric switch



R. A.' MILLERMASTER ELECTRIC SWITCH Original Filed July 10, 1936 2Sheets-Sheet I LOAD LOAD

R. A. MILLERMASTEQ 2,125,684

ELECTRIC SWITCH Original Filed July 10, 1936 2 Sheets-Shem. 2

Patented Ann. 2, i938 anneal hlthifl'lihlfi hllt'i'iilh Match All.ltiilllermaster, lliillwanhee, Win, asslgnorto hotter-Hammer, line,

notation of heiaware teem lliiilwauhee, Wis, a cororiginal anpiication.lniy no, rose, Shi'l'ldil No. cases, now Patent No. httih'llit, datedhugnst 2i,-li9tt'. lhivided and this application .lnly 2t,

ll iliainis.

This invention relates to improvements in elec tric switches, and theinvention relates more particularly to electric safety switches oi thesnap type. it

tion of switches of the aforementioned character. another object is toprovide an arc snufier' which is particularly well adapted for use witha m switch of the free-end, knife-blade type.

Another object is to provide improved and siniplifiedmeans for effectingsnap operation of the switch to open-circuit or closed-circuit positionof the parts. w Another object is to provide an improved tor-in ofoperating handle and handle attachingmeans tor switches of theaforementioned character.

Uther objects and advantages oi the invention will hereinafter appear.

This application is a division oi my copencling application, Serial llo. tilttt, flied July it), with, for improvement in Electric switches,which has resultedjln Patent iiio. Eilhilflii'i', elated. ring. it,

lhe accompanying drawings illustrate a preferred embodiment of theinvention which will now he described, it being understood that theembodiment illustrated is susceptible of modification in respect ofcertain structural details thereof without departing from the scope oithe appended claims.

in the drawings, Figure l is a top plan view, hali-size, of an enclosedor safety switch at the snap type-the hinged cover of the sheet metalcasing of the switch being shown tragmentarily in open position,--and aportion of the side wall of the casing which carries the cover latchbeing hrolren away.

Fig. 2 is a fragmentary vertical sectional view,

" slightly greater than normal size, on the line 2-412 of Fig. 1,showing in detail the interlocking ii-it Fig. 3a is a fragmentaryelevational view of certain of the parts, looking in the direction ofthe arrows 3 -3 of Fig. 3. r

Fig. 4 is a side elevational view of certain of the switch parts shownin Fig. l,the switch cashn' object of the invention is to generallyimprove the details of construction and the opera- (ill. WM?) ing losingoniitted,-and certain of the parts heing hrolren away or in section.

his. 51s a fragmentary elevational view, as seen from the right-handside of the device in Fig. i.

Fla. ii is a fragmentary elevational view oi certain oi the switchparts, as seen from the opposite side of the casing wall in Fig. 5, and

Fig. 'i is a side elevational view, on a reduced scale, oi one of theduplicate insulating arc snufling elements, showing the term oi therecess walls,

which are shown in section in Fig. i.

Referring to the drawings, the numeral it designates a hose molded ironsa suitable insulating material to the form illustrated in Figs. 1 andBase it when positioned within the sheet metal housing ii is rigidlyattached to the hottom wall ii oi the latter, as toy means of threeholts each designated by the numeral it. The switch herein illustratedis of the denialsole type,--hut it is to he understood that my inventionis applicable to switches having any desired nnn'lher of poles. Ease itis provided on its upper surface adjacent to one end thereof with a pairoi metal hiocks or plates it oi approximately L-shape which are attachedthereto icy holts iii (Fig. i) and it) (Figs. 1 and 4). Each bolt itwith its not li (Fig. i) likewise provides for attachment oi the post orsupport it which pivotally carries one end. of a hnifc hlade contactorit. Each bolt it with its nut li likewise provides for at tachment of atuhular soldering terminal element iii ot'well known iorin.

Each contactor' ll preferably has attached to opposite sides thereof, byrivets i ii, a pair oi relatively thin flat insulating plates it oflilreform. "the projecting lower ends of said plates 2t are adapted toengage the rih it formed upon the upper surface of base it to limit thecircuit closing movement of the contactors (see Fig. l). Plates it areprovided with slots or notches opening in a direction away from thepoint of pivotal, support of the contactor, as shown at til in Fig. i.Said notches are adapted to accommodate the crank portion of a switchactuating element it, said crank portion preferably having tele-' scopedthereonto prior to bending of element it an insulating tube ittorproperly insulate said element from the contactors.

Arrangedin spaced relation to the pivot posts it are a pair oi one-pieceresilient sheet metal contacts it oi identical form, as shown in sectionin Fig. 2 and in dotted lines in Fig. i. Con-o tactsit are ofconstricted U-shape in vertical means of a bolt 24 the threaded shank ofwhich extends upwardly through a passage in base Hi, penetrates anopening provided in the base portion of the contact, and takes into atapped opening in a metal plate 25. Plate is further attached to base Inby a bolt 26 the shank of which threads into a second tapped opening insaid plate. Said shank extends upwardly a sufiicient distance topenetrate a clearance opening provided in the tubular soldering terminalelement 21 of well known form,a nut 215 cooperating with said shank toclamp terminal 21 in fixed position.

To minimize arcing between each contact 23 and its cooperating contactorl1, and to thereby increase the life, the current controlling capacityand the safety characteristics of the switch as a whole, I provide foreach contact 23 an arc snufllng device designated in general by thenumeral 28. Each of said devices comprises a pair of members 28 ofidentical form which are preferably molded from a suitableheat-resisting insulating material. The adjacent faces of members 28*-are complementaliy recessed, as shown in Figs. 2 and 7 to jointlyaccommodate all parts of the stationary contact 23 associatedtherewith,-the arrangement being such that in the open circuit positionof contactor I? the adjacent faces of members 28* may be brought intoengagement with each other to completely enclose the contact 23. Members28 are normally biased toward each other by a substantially U shapedresilient metal clip 29 the respective arms of which seat in grooves 28of correspond ing shape upon the outer surfaces of the respectivemembers 28* between the upperand lower ends of the latter. The free endsof the arms of member 29'are flared, as shown-at 25- in Fig. .4, tofacilitate insertion thereof into said grooves. Members 2i! are likewisepreferably provided at the forward and rear sides thereof withcomplementary recesses 28 and 28, any pair of which are adapted toaccommodate at least parts of the connecting portion 29 of member 28(see Fig. 4). Each arm of member 2! is preferably provided with aninwardly extending hemispherical boss or projection, and each groove It"is provided with a pair of hemispherical depressions, located atcorresponding distances from the respective ends thereof to selectivelyaccommodate said bosses, whereby accidental separation of clip 29 frommembers 28* is prevented. One of said depressions is shown in dottedlines at 28 in Fig. 4. As will be understood, the member 29 is soassembled with respect to the members 28' that the connecting portion 29is at the end of, said members which is remote from the pivot point ofcontactor IT. The members 28!, however, may be" reversed with respect tocontact 23 and with respect to clip 2|.-

The members 28' of the arc'snuflinz device are restrained againstsubstantial sliding movement 1 mentioned horizontal tongues 2v; 2: (Fig.2).,

The arrangement is such that upon initial engagement of each contactor Hwith the beveled edges 28'. 28" of members 22 the upper ends 28 of thelatter will be spread apart against the bias of member 29, and uponcontinued circuit closing movement of contactor ll the members 28 willassume the positions thereof shown in Figs. 1 and 2. That'is to say, theforward edges of said members will be spread apart to the requireddegree to accommodate contactor l1 whereas the rear edges thereof willbe biased into engagement-with each other. As hereinafter described, Ipreferably provide means for effecting movement of contactors H toopposite extreme positions thereof with a snap action, and the aresnuifing members 28 and members 29 are so constructed and arranged as.to add only a negligible amount of resistance to such movements of thecontactors.

The switch actuating mechanism is preferably so constructed that in theevent of breakage or disablement of the snap action spring, thecontactors ll maybe moved to open-circuit position by manual operationof the switch handle,

but in such event the contactors l1 may not be moved to circuit-closingposition pending repair or replacement of the snap action spring. It isto be understood that the snapaction mechanism is adapted to becomeeffective upon the contactors ill just prior to disengagement of thelatter from the stationary contacts, wherefore the subsequent rapidmovement of said contactors between the relatively large fiat surfaces28 on members 28 will tend to cool and extinguish any arcs formedincident to separation of the contactors from the contacts. Moreover,when in the circuit interrupting movement of contactor-s ii the same aredisengaged from members 28 the entire adjacent fiat faces of the latterwill be snapped into engagement with each other, under the bias' of therespective members 29, thus completely enclosing the contacts 23 withwhich they are associated to further assist in and insure quenching orsnufiing of any arcs so forrried.

The switch herein described and illustrated has a rating of 100 amperesat 575 volts A. C. It if it desired to provide a switch of substantiallylower rating or current controlling capacity, the arc snufling devices,including members 28 and29 may be entirely omitted without in anywiseaffecting the construction or assembly of the other switch parts.Moreover, the arc snufiing devices may be readily removed to permitinspection, repair or replacement of the respective contacts by merelymanually withdrawing the members 29, whereupon the members 28 are freeto be removed laterally from their associated contacts. Or the member 29of each arc snumng device may be permitted to remain in position and theforward edges of members 28 may be spread apart manually to effectvdisengagement of the lower walls of auxiliary recesses 20 from thetongue 23, 23 whereupon the complete arc snuffing device may be liftedvertically out of interlocking engagement with its contact 23. Thereverse of this procedure may, of course,

be followed in assembling the arc snufling devices with respect to theirassociated contacts.

The switch operating mechanism includes a hub member 30 having arelatively large circular end portion 30 one flat face of which isadapted to bear against the adjacent flat face of a punched and stampedsheet metal member 3!, the other face of the latter being adapted tobear against the inner surface of the side wall N of the switch casing(Fig. 3). Member 3! is provided with an opening 3i, the form of which issilenced illustrated in Fig. 3a. "I'hemain portionof the peripheral wallof opening Si is in .the form of an arc of a circle, to provide abearing forthe arc-shaped peripheral edge of the reduced portion 3t! oftheihub member: Saidportion 30 is also provided with a fiat' edge'30,and the hub member 30 and member 3!. Member 3| is provided with integralportions 3| 3! which are slightly oifsetfrom the main body thereof(Figs.

thereof is a flange M said crank: member.

3 and 3a) to minimize friction between said member and the inner surfaceof casing. wall it. The portion M is provided with an integral lug 3iwhich is bent inwardly at substantially a right angle with respect tosaid casing wall, and the portion 3i is similarly provided with anintegral lug ii. The lugs ti ti are spaced a predetermined distanceapart and in overlapping rela- Fionship to one arm of crank member 2i,as best llustrated in Fig. 1,-to provide a predetermined degree of lostmotion between member 3! and Casing wall li is providedgwith a 'circularopening "li (Fig; 3) rand l prefer to position within said'opening'in-bear- 7 ing relationship to the wall thereof a circular washer (i2,saidwasher being of slightly greater thickness than wall it, for a purposeto be described.

Hub member 30 is provided with a. further reduced portion 30 of thecontour best illustrated inFig. 3a,-the same having parallel flat sidesW and 30. Washer 32 is provided with an opening of a shape correspondingto the cross sectional-contour of portion 30 whereby these parts areconstrained to rotate with each other.

The operating handle 33 is non-'rotatably at-, tached to hub member ddin the following manner: A stamped sheet metal member having a main bodyportion 3d of substantially circular [contour is adapted to seat againstthe outer surface of washer 32 (Fig. 3), and said portion is providedwith an opening to non-rotatably accommodate the portion 30 of the hubmember. The handle 33 is provided with a portion 33 of invertedchannel-shape which overlies said body portion 34 in the relationshipbest illustrated in Fig. 5,it being understood that the longitudinalcenter line of handle 33 is parallel with the fiat sides db and 30 ofhub portion 3W Interposed between handle portion 33 and body portion 34is a. pair of spaced metal membars 35 and 36, all of said elements beingrigidly attached to each other, as by means of four rivets til, thetapered heads of which (not shown) are positioned in counterslnks in thesurface of portion t t adjacent to casing wall ii.

Formed integrally with the portion 3t and surrounding the major portionof the periphery Also formed integrally with portion M is a projectionor lug iid which is angled away from casing wall it? to a slight degree,as shown in Fig. l. The shoulder provided at one end of projection 3 tis adapted I to abut against the edge of a' right-angled lug tileforming part of a bracket member M which is rigidly attached to wall i las by means of rivets 39 (see Fig. to positively limit the degree ofrotary'movement of handle it in one direction. The shoulder provided atthe other end of projection 34 is adapted to abut against the edge of arighteangied lug 40" forming part to wall It, as by means of rivets ti.The lugs 33 d 40 are respectively provided with periorati ns shown,respectively, in dotted lines at 38 and M1 in Fig. 5; and flange GM isprovided with a perforation 3t and a notch tit (see Figs. 3 and 5),which are selectively registerable with the aforementionedlug openings38', fiit to provide for insertion of the hasp of a padlock of suitableform, whereby the switch may be locked in open-circuit or closed-circuitposition.

As best shown in Fig. 3, the handle portion 33 is provided with anopening to afiord clearance for the still further reduced and threadedend portion 30 of thehub member, a nut 42 being engaged with portion tilto clamp the aforedescribed parts in assembled relation. Portion 38' ispreferably provided with one or more drilled passages (seeFigs. 3 and3a) extending diametrically therethrough adjacent to the outer endthereof, and nut M is provided with a. plurality of kerfs extending fromthe outer end thereof to provide for insertion of a cotter pin 433, inthe manner illustrated in Figs. 3 and 5, whereby loosening of nut M ispositively prevented.

-To limit the degree of circuit-interrupting movement of contactors it,I prefer to pro- 3 of a bracket membeMiPwhich is rigidly attached vide astud M projecting inwardly from the V casing wallv H to be engaged bythe right-hand arm of crank member iii (see Figs. 1 and 6).

The reduced and M of stud it penetrates an opening provided in wall Nand a washer t5 and is upset over the latter, as shown in Figs. 1 and 5.

Referring to Figs. '1, 3a and 6, it will be noted that the portion di ofmember iii is provided I with an integral offset lug 3B which isprovided with an opening to register with openings provided in theenlarged and shouldered ends of a pair of metal members it and Warranged on opposite sides thereof,a headed rivet #8 being insertedthrough said openings-and upset as shown to provide a pivotal connectionbee tween said parts. Members at and M are offset into engagement witheach other throughout the major portion of the length thereof from apoint adjacent to the pivot end thereof,the 7 free ends of said membersbeing reciprocable through an opening provided in the lug th formingapart of bracket M which is attached to casing wall li as by means ofrivets 5i). Lug ta is formed to provide a pair of surfaces angled towardeach other to provide a sort of knifeedge bearing for one end of acoiled compression spring 5|! which surrounds members 46 and i'i,-theother end of said spring being engaged with the aforementioned shouldersat the enlarged ends of members it and M.

A latch member 52 is pivotally supported in spaced relation to casingwall it, as by means of pin 53 (Fig. 6),-a bracket M being attached tosaid wall, as by means of rivets 55. The horizontal portion M of saidbracket has an opening to provide clearance for latch 52 and to insureproper alinement thereof with an opening or slot (not shown) provided inthe casing cover M Member 52 is provided on the portion 5?! thereof withan abutment to accommodate and retain one end of a coiled compressionspring-th other end of which engages a boss or abutment formed upon thelower face of the horizontal portion 5d of said bracket. Latch 52 isalso preferably provided with an opening 52' to accommodate the has'p ofa suitable padlock, to proprevent complete closure thereof, if desired.

The handle 33 which is formed of sheet metal has the grip portion 33"thereof drawn or swaged V tothe hollow form illustrated, and in amannerto avoid exposure of any out edges;

It is thought that the operation of the snap switch mechanism will beobvious from the foregoing description. It may be pointed out, however,that with the various parts in the respective closed-circuit positionsshown in Figs. 1

and 5, upon initial downward movement of handle 33, the lost motionbetween the hub member and member I is first taken up. That is to say(see Fig. 3c), the hub 30 is permitted to move rather freelyuntil thefiat edge 30 of hub portion 30 engages the flat wall portion 3 ofLetters Patent is:

opening 3!. Thereupon member 3! rotates along with hub member 30 toefiect compression of spring 5!. Before the toggle (represented by thepivot pin 48) reaches dead center the lug ll (Figs. 1 and 6) will engagethe right-hand arm of crank .member H to positively initiatedisengagement of contactors H from their associated stationary contacts23. As heretofore pointed out, said contactors ll may be disengaged bythe operating means independently of spring 5|,but under normalconditions spring 5! will become effective prior to completedisengagement of said contactors to effect snap movement thereof tocircuit interrupting position. Such movement of contactors i1 is limitedby engagement of crank member 2| with stop pin 44, as aforedescribed.The are snufling devices will act in the manner aforedescribed tominimize the de-' gree of arc formation and to efiectually extinguish orsnuff any arcs formed incident to the operation.

What I claim as new and desire to secure by 1. In an electric safetyswitch, in combination, a sheet metal casing having an openable cover, ametal bracket secured to the inner surface of one side wall of saidcasing, said bracket having a pivot opening formed therein, a crankmember having one end thereof pivotally supported within said bracketopening, the opposite side wall of said casing having a relatively largeopening formed therein in alinement with said bracket opening, a washeradapted to bear within said last mentioned opening, a hub member havinga. relatively large end portion located.

within said casing, said end portion having a recess adapted to providea bearing for the other end of said crank member, a switch actuatingelement having a portion thereof interposed be? tween said hub end and.the last mentioned side wall of the casing, said element and said hubmember being cooperatively formed to provide a predetermined degree oflost motion therebetween, said element having spaced lugs formedintegrally therewith to provide a predetermined degree of lost motionbetween the same and said crank member, said hub member having a portionof non-circular cross section projecting from said casing, a stampedsheet metal member having an opening therein corresponding in shape tosaid last mentioned hub portion to provide a positive driving connectiontherebetween, a sheet metal handle member having a portion of invertedchannel-shape superimposed upon said stamped sheet metal member andrigidly attached thereto, said portion of the handle member having anopening formed therein, said hub member having a reduced and threadedend vide for locking cover H in closed position, or to portion extendingthrough said opening, and a nut engaging said threaded end and havingclamping engagement with said handle portion to retain the latter andsaid hub member in assembled relation to said casing. l

2. In an electric safety switch, in combination, a sheet metal casinghaving an openable cover, a metal bracket secured to the inner surfaceof one side wall of said casing, said bracket having a pivot openingformed therein, a crank member having one end thereof pivotallysupported within said bracket opening, the opposite side wall of saidcasing having a relatively large opening formed therein in alinementwith said bracket opening, an annular washer adapted to bear within saidlast mentioned opening, a hub member having a relatively large endportion 10- cated within said casing, said end portion having a recessadapted to provide a bearing for the other end of said crank member, aswitch actuating element having a portion thereof interposed betweensaid-hub end and the last mentioned side wall of the casing, saidelement and said hub member being cooperatively formed to provide apredetermined degree of lost motion therebetween, said element havingspaced lugs-formed integrally therewith to provide a predetermineddegree of lost motion between the same and said crank member, said hubmember having a portion of non-circular cross section projecting fromsaid casing a stamped sheet metal member having an opening thereincorresponding in shape to said last mentioned hub portion to provide' apositive driving connection .therebetween, a sheet metal handle memberhaving a portion of inverted channel-shape superimposed upon saidstamped sheet metal member and rigidly attached thereto, said portion ofthe handle member having anfopening formed therein, said hub memberhaving a reduced and threaded end portion extending throughsaidvopening, a nut engaging said threaded end and having clampingengagement with said handle portion to retain the latter and said hubmember in assembled relation to said casing, said threaded end having adiametrical passage formed therein, said nut having a plurality of slotsformed therein to selectively register with said passage, and a cotterpin cooperating with saidslotsand said passage to restrain said nutagainst separation from said hub member.

3. In an electric safety switch, in combination, a sheet metal casinghaving an openable cover, ametal bracket secured to the inner surface ofone side wall of said casing, said bracket having a pivot opening formedtherein, a crank member having one end thereof pivotally supported--within said bracket opening, the opposite side hub end and the lastmentioned side wall of the casing, said element and said hub memberbeing cooperatively formed to provide a predetermined degree of lostmotion therebetween, said element having spaced lugs formed integrallytherewith to provide a predetermined degree of lost motion between thesame and said crank member, said hub member having a portion ofnon-circular cross section projecting from aiaaesa.

said

casing, a stamped sheet metal member having an opening thereincorresponding in shape to said ,last mentioned hub portion to provide apositive driving connection therebetween, a sheet metal handle memberhaving a portion of inverted channel-shape superimposed upon saidstamped sheetrnetal member and,rigidly attached thereto, said portion ofthe handle member having an opening formed therein, said hubrnemberhaving a reduced and threaded end portion extending through saidopening, a nut engaging said threaded end and having clamping engagementwith said handle portion to retain the latter and said hub member inassembled relation "to said casing, said switch actuating element havinga lug formed integrally therewith and located in'a plane parallel to andoffset from the main body thereof, a pair of sheet metal rods pivotallyattached at one end thereof to said lug, said rods having shouldersformed thereon adjacent to the pivot point thereof, a bracket member sevcured to said'casing wall and having an opening to receive and guidesaid rods, and a coiled compression spring interposed between saidbracket and said shoulders to insure snap movement of said element toeach of its extreme" positions.

4. In an electric safety switch, in combination, a sheet metal casinghaving an openable cover, a metal bracket secured to the'inner surfaceof one side wall of said casing, said bracket having a pivot openingformed therein, a crank memher having one end thereof pivotallysupported within said bracket opening, the opposite side Wall of saidcasing having a -relatively large opening-formed therein in alinementwith said bracket opening, a washer adapted to bear within said lastmentioned opening, a hub member having a relatively large end portionlocated within said casing, said end portion having a recess adapted toprovide a bearing for the other end of said crank member, a switchactuating element having a portion thereof interposed between said hubend and the last mentioned side wall of the casing, said element andsaid hub member being cooperatively formed to provide a predetermineddegree of lost motion therebetween, said element having spaced lugsformed integrally therewith to provide a predetermined degree of lostmotion between the same and said crank member, said hub member having aportion of non-circular cross section projecting from said casing, astamped sheet metal member having an opening therein corresponding inshape to said last mentioned hub portion to provide a positive drivingconnection therebetween, said stamped sheet metal member having anextension formed integrally therewith and adapted to provide a pair ofspaced substantially radial shoulders arranged at a slight angle to theouter surface of said casing wall, and a pair of lug members rigidlyattached to said outer surface of the casing wall and respectivelyadapted for engagement by said shoulders to positively limit movement ofsaid member in opposite directions.

5. In an electric safety switch, in combination, a sheet metal casinghaving an openable cover, a metal bracket secured to the inner surfaceof one side wall of said casing, said bracket having a pivot openingformed therein, a crank member having one end thereof pivotallysupported within said bracket opening, the opposite side wall of saidcasing having a relatively large opening formed ther'ein in alinementwith said bracket opening an annular washer adapted to bear within saidlast mentioned opening, a hub member having a relatively large endportion located within said casing, said end portion having a recessadapted to provide a bearing for the other end of said crank member, aswitch actuating element having a portion thereof interposedbetween'said hub end and the last mentioned side wall of the casing,said element and said hub member being cooperatively formed to provide apredetermined degree of lost motion therebetween, said element havingspaced lugs iormed integrally therewith to provide a predetermineddegree of lost motion between the same andsaid crank member, said hubmember having a portion of non-circular cross section projecting fromsaid casing, a stamped sheet metal memberhaving an opening thereincorresponding in shape to said last mentioned hub portion to provide apositive driving connection therebetween, said stamped sheet metalmember having an extension formed integrally therewith and adapted toprovide a pair of spaced substantially radial shoulders arranged at aslight angle to the outer surface of said casing wall, a pair of lugmembers rigidly attached to said outer surface of the casing wall andrespectively adapted for engagement by said shoulders to positivelylimit movement of said member in opposite directions, said lug membershaving openings formed therein, said member having an upstanding flangeformed integrally therewith between portion of non-circular crosssection adapted to penetrate said metal member and projecting from saidcasing, a switch actuating element having a portion thereof interposedbetween said hub end and the inner surface of said side wall of thecasing, said element and said hub member being cooperatively formed toprovide a predetermined degree of lost motion therebetween,

said element having spaced lugs formedintegrally therewith to provide apredetermined degree of lost motion between the same and said crankmember, a stamped sheet metal member having an opening thereincorresponding in shape to said projecting hub portion to provide apositive driving connection therebetween, a metal handle member having aportion of inverted channelshape superimposed upon said stamped sheetmetal member and rigidly attached thereto, said portion of the handlemember having" an opening formed therein, said hub member having areduced and threaded end portion extending through said opening, and anut engaging said threaded end and having clamping engagement with saidhandle portion to retain the latter and said hub member in assembledrelation to each other.

7. In a snap make and break electric safety switch, in combination, ametal enclosing casing, a crank member pivotally supported within saidcasing, one side wall of said casing having a relatively large openingformed therein in alinement with the pivotal center of said crankmember, a metal member of circular contour adapted to bear within saidopening, a machined metal hub member having a relatively large endportion located within said casing and an intermediate portion ofnon-circular cross section adapted to penetrate said metal member andprojecting from said casing, a switch actuating element having a portionthereof interposed between said hub end and the inner surface of saidside wall of the casing, said element and said projecting A portion ofthe hub member being cooperatively formed to provide a predetermineddegree of lost motion therebetween, said element having spaced lugsformed integrally therewith to provide a predetermined degree of lostmotion between the same and said crank member, a stamped sheet metalmember having an opening therein correspending in shape to saidprojecting hub portion to provide a positive driving connectiontherebetween, a metal handle member having a portion of invertedchannel-shape superimposedupon said stamped sheet metal member andrigidly attached thereto, said hub member having a reduced end portionpenetrating said, portion of the handle member and projectingtherebeyond, means associated with said reduced end portion of the hubmember to retain said handle member in assembled relation to the latter,said switch actuating element having an additional lug formed integrallytherewith, a metal rod member pivotally connected at one end thereof tosaid last mentioned lug, said rod member-having shoulders formed thereonadjacent to the pivot point theretion type, in combination, a metalenclosing cassponding contour adapted to bear edgewise with v ing, abail-shaped crank member pivotally supported within said casing, oneside wall of said casing having a relatively large circular openingformed therein, a flat metal member of correin said opening, a machinedmetal hub member having a relatively large end flange located withinsaid casing, a punched and stamped sheet metal switch actuating elementhaving a portion directions.

thereof interposed between said hub flange and the inner surface of saidside wall of the casing, said element and said hub having shouldersformed thereon to provide a predetermined degree of lost motiontherebetween, said element having a pair of angularly spaced lugs formedintegrally therewith to 'provide a predetermined degree of lost motionbetween the same and said crank member, said hub member having a portionof non-circular cross section projecting from said casing, a punched andstamped sheet metal member having an opening formed thereincorresponding in shape to said last mentioned hub portion to provide arigid and positive driving connection therebetween, said last mentionedsheet metal member having an extension formed integrally therewith andadapted to provide a pair of spaced angular shoulders, and a pair of lugmembers rigidly attached to said casing wall and-adapted for engagementby said shoulders respectively to limit movement of said memberin-opposite directions.

9. In actuating means for electric switches, in combination, a metalenclosing casing having an opening formed in one side wall thereof, amachined metal hub member penetrating said opening and having arelatively large end flange located within said housing, a bail-shapedcrank member one end of which is pivotally supported by said hub member,a. switch actuating element having a portion thereof interposed betweensaid end flange of the hub member and said side wall, said element andsaid hub being cooperatively formed to provide a, predetermined degreeof lost motion therebetween, said elementhaving spaced lugs formedintegrally therewith to provide a predetermined degree of lostrnotionbetween the same and said crankmember, said hub member having a portionof non-circular cross section projecting from said casing, a metalmember having an opening therein corresponding in shape to said lastmentioned'hub portion to. provide a rigid and positive drivingconnection therebetween, said lastmentioned metal member having anextension formed integrally therewith to provide a'pair of, spacedangularly arranged shoulders, and meansncarried by said side wall of thecasing" to be engaged'bysaid shoulders to positively limit movement ofsaid member in opposite RALPH A. MIILERMAS'I'ER.

